Allow targets to specify their choice of calling conventions per

libcall. Take advantage of this in the ARM backend to rectify broken
choice of CC when hard float is in effect. PIC16 may want to see if
it could be of use in MakePIC16Libcall, which works unchanged.

Patch by Sandeep!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79033 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 44 insertions, 6 deletions

diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 5a05c8c37b..fda362d8ce 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -22,6 +22,7 @@
 #ifndef LLVM_TARGET_TARGETLOWERING_H
 #define LLVM_TARGET_TARGETLOWERING_H
 
+#include "llvm/CallingConv.h"
 #include "llvm/InlineAsm.h"
 #include "llvm/CodeGen/SelectionDAGNodes.h"
 #include "llvm/CodeGen/RuntimeLibcalls.h"
@@ -1539,6 +1540,18 @@ public:
     return CmpLibcallCCs[Call];
   }
 
+  /// setLibcallCallingConv - Set the CallingConv that should be used for the
+  /// specified libcall.
+  void setLibcallCallingConv(RTLIB::Libcall Call, CallingConv::ID CC) {
+    LibcallCallingConvs[Call] = CC;
+  }
+  
+  /// getLibcallCallingConv - Get the CallingConv that should be used for the
+  /// specified libcall.
+  CallingConv::ID getLibcallCallingConv(RTLIB::Libcall Call) const {
+    return LibcallCallingConvs[Call];
+  }
+
 private:
   TargetMachine &TM;
   const TargetData *TD;
@@ -1705,6 +1718,10 @@ private:
   /// of each of the comparison libcall against zero.
   ISD::CondCode CmpLibcallCCs[RTLIB::UNKNOWN_LIBCALL];
 
+  /// LibcallCallingConvs - Stores the CallingConv that should be used for each
+  /// libcall.
+  CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL];
+
 protected:
   /// When lowering \@llvm.memset this field specifies the maximum number of
   /// store operations that may be substituted for the call to memset. Targets
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index ab4ebefa30..66469ef3c9 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1869,7 +1869,7 @@ SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
   const Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
   std::pair<SDValue, SDValue> CallInfo =
     TLI.LowerCallTo(InChain, RetTy, isSigned, !isSigned, false, false,
-                    0, CallingConv::C, false,
+                    0, TLI.getLibcallCallingConv(LC), false,
                     /*isReturnValueUsed=*/true,
                     Callee, Args, DAG,
                     Node->getDebugLoc());
diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index 11ec9f168c..1518317328 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -1019,7 +1019,7 @@ SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, EVT RetVT,
   const Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   std::pair<SDValue,SDValue> CallInfo =
     TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
-                    false, 0, CallingConv::C, false,
+                    false, 0, TLI.getLibcallCallingConv(LC), false,
                     /*isReturnValueUsed=*/true,
                     Callee, Args, DAG, dl);
   return CallInfo.first;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index afcbc0987b..5d4717ac59 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3390,7 +3390,8 @@ SDValue SelectionDAG::getMemcpy(SDValue Chain, DebugLoc dl, SDValue Dst,
   // FIXME: pass in DebugLoc
   std::pair<SDValue,SDValue> CallResult =
     TLI.LowerCallTo(Chain, Type::getVoidTy(*getContext()),
-                    false, false, false, false, 0, CallingConv::C, false,
+                    false, false, false, false, 0,
+                    TLI.getLibcallCallingConv(RTLIB::MEMCPY), false,
                     /*isReturnValueUsed=*/false,
                     getExternalSymbol(TLI.getLibcallName(RTLIB::MEMCPY), 
                                       TLI.getPointerTy()),
@@ -3438,7 +3439,8 @@ SDValue SelectionDAG::getMemmove(SDValue Chain, DebugLoc dl, SDValue Dst,
   // FIXME:  pass in DebugLoc
   std::pair<SDValue,SDValue> CallResult =
     TLI.LowerCallTo(Chain, Type::getVoidTy(*getContext()),
-                    false, false, false, false, 0, CallingConv::C, false,
+                    false, false, false, false, 0,
+                    TLI.getLibcallCallingConv(RTLIB::MEMMOVE), false,
                     /*isReturnValueUsed=*/false,
                     getExternalSymbol(TLI.getLibcallName(RTLIB::MEMMOVE), 
                                       TLI.getPointerTy()),
@@ -3496,7 +3498,8 @@ SDValue SelectionDAG::getMemset(SDValue Chain, DebugLoc dl, SDValue Dst,
   // FIXME: pass in DebugLoc
   std::pair<SDValue,SDValue> CallResult =
     TLI.LowerCallTo(Chain, Type::getVoidTy(*getContext()),
-                    false, false, false, false, 0, CallingConv::C, false,
+                    false, false, false, false, 0,
+                    TLI.getLibcallCallingConv(RTLIB::MEMSET), false,
                     /*isReturnValueUsed=*/false,
                     getExternalSymbol(TLI.getLibcallName(RTLIB::MEMSET), 
                                       TLI.getPointerTy()),
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 767238e781..3414fee7d4 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -247,6 +247,14 @@ static void InitLibcallNames(const char **Names) {
   Names[RTLIB::UNWIND_RESUME] = "_Unwind_Resume";
 }
 
+/// InitLibcallCallingConvs - Set default libcall CallingConvs.
+///
+static void InitLibcallCallingConvs(CallingConv::ID *CCs) {
+  for (int i = 0; i < RTLIB::UNKNOWN_LIBCALL; ++i) {
+    CCs[i] = CallingConv::C;
+  }
+}
+
 /// getFPEXT - Return the FPEXT_*_* value for the given types, or
 /// UNKNOWN_LIBCALL if there is none.
 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
@@ -520,6 +528,7 @@ TargetLowering::TargetLowering(TargetMachine &tm,TargetLoweringObjectFile *tlof)
 
   InitLibcallNames(LibcallRoutineNames);
   InitCmpLibcallCCs(CmpLibcallCCs);
+  InitLibcallCallingConvs(LibcallCallingConvs);
 
   // Tell Legalize whether the assembler supports DEBUG_LOC.
   const TargetAsmInfo *TASM = TM.getTargetAsmInfo();
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 9138c5730c..a4471000b0 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -201,6 +201,15 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
   setLibcallName(RTLIB::SRL_I128, 0);
   setLibcallName(RTLIB::SRA_I128, 0);
 
+  // Libcalls should use the AAPCS base standard ABI, even if hard float
+  // is in effect, as per the ARM RTABI specification, section 4.1.2.
+  if (Subtarget->isAAPCS_ABI()) {
+    for (int i = 0; i < RTLIB::UNKNOWN_LIBCALL; ++i) {
+      setLibcallCallingConv(static_cast<RTLIB::Libcall>(i),
+                            CallingConv::ARM_AAPCS);
+    }
+  }
+
   if (Subtarget->isThumb1Only())
     addRegisterClass(MVT::i32, ARM::tGPRRegisterClass);
   else
diff --git a/lib/Target/CellSPU/SPUISelLowering.cpp b/lib/Target/CellSPU/SPUISelLowering.cpp
index be3030d556..84dbb6a9a0 100644
--- a/lib/Target/CellSPU/SPUISelLowering.cpp
+++ b/lib/Target/CellSPU/SPUISelLowering.cpp
@@ -116,7 +116,7 @@ namespace {
                 Op.getNode()->getValueType(0).getTypeForEVT(*DAG.getContext());
     std::pair<SDValue, SDValue> CallInfo =
             TLI.LowerCallTo(InChain, RetTy, isSigned, !isSigned, false, false,
-                            0, CallingConv::C, false,
+                            0, TLI.getLibcallCallingConv(LC), false,
                             /*isReturnValueUsed=*/true,
                             Callee, Args, DAG,
                             Op.getDebugLoc());